Can I Fix this 46 Year Old Computer? | Commodore KIM-1 Repair

Edit: Sorry about the background music. I dialed it to -35db and somehow in processing on YT it perked up again. There's a lot of free background music on offer out there for YTers but so much of it has obnoxious segments - trumpets, guitar, drums, pianos, etc. I get that the artists (whom I am grateful for) dont want to be boring, but that's kind of what we want background music to be. I wouldn't mind trying something other than slow jazz but there's just not a lot out there that fits as proper background music, and I feel like the right music makes the video feel more professional. Anyway, next video I will assassinate any loud instrument solos I come across. Sorry it's been.. um.. a really long time.. but, life happens. Anyway, I managed to squeeze this little side project in, filmed and edited in record time. Sorry - no animations/3d.. it would have added weeks to this and Youtube would bomb it anyway. But the next video will have those, and it's not far from being finished!

Probably around 1986, when they were still being used in university computer labs to teach wiring up your own digital circuits. Crazy advanced stuff like adding massive amounts of memory to it. I didn't have the lab, but my girlfriend did, and she showed me her Kim-1 station in the lab where every student had one. I was a mad software hacker back then, but I was like dang, I had no clue you were off the chain as a hardware hacker. I just though she was an intense physics and math nerd. Cern never hired her, but she later got a job at Intel writing device drivers. I could assembly level program my C=64 back in my dorm, but this girl after her Kim-1 lab could not only assembly program one, but friggin build one as if she were Bill Herd

You got it running. Not get Doom running on it. 🤣🤣🤣

The KIM-1 literally looks like a time machine board, fitting with your channel name.

The KIM-1 was the first computer I ever programmed. My high school electronics class had one that nobody had played with. This would have been 79 or 80, long time ago. It was in a wooden box with a smoked plexiglass cover. I thought the chips were socketed on it, but again, long time. I'm sure I typed in that exact program and a bunch of others that were in the Xeroxed manual, although I think it was spiral or comb bound. I thought it was the coolest thing in the world at the time. I wanted to take computer classes but they insisted I had to take advanced algebra as a pre-requisite. I didn't do well, I was so mad at being forced to take the class that I copped an attitude and ditched class... to go hang out in the electronics lab! Needless to say, didn't pass that class so I couldn't take any computer classes. I ended up begging my parents for a computer kit in the back of Popular Electronics. It was expensive (for the time), but since it was educational, I got it for Christmas. It turned out to be a Sinclair ZX-80 with a whopping 1K of memory! The best thing about it was it forced me to learn machine language due to its efficiency. 40+ years of programming computers and micros, I have as of yet to apply anything that was taught in that advanced algebra class in anything I've done. Calculus would have come in quite handy (PID loops, Fourier transforms), but advanced algebra has been worthless.

I bought mine in 1977. Built a s100 motherboard for it. Good times.

I'd still highly reccomend the Hakko desoldering gun. It's expensive, but the time and frustration saved is more than worth the cost of entry. I use mine almost daily, and i'll never go back to the manual solder sucker. Great video, as always!

Not seen yet- thumbs up! Your channel is my absolute favourite one. Best regards from an absolute CBM/PET guy in germany! ;)

Well done with the repair. In 1977 there were (almost) no home computers. Enthusiasts jumped on the affordable and expandable KIM-1. 4k expansion boards were simple. Connecting to a teletype was simple. Programs were hand compiled into 6502 machine language with paper and pencil. For the first time a regular person could buy a pre assembled computer and learn how they work. That's what makes the KIM-1 special.

I just love that end 70's era "analogue" routing!

Congrats on the successful rescue! Reminds me of my own multi-year effort to get my TIM-1 system (based on the MAI "Jolt" with a 6530-004 chip) running reliably. It would run for a while, then refuse to fully boot. Finally tracked it down to a marginal jelly-bean 74xx chip and a bad socket. Sheesh. The key piece of troubleshooting equipment was an HP 1662 logic analyzer with which I could watch the CPU trying to run, then fly off into hyperspace. The bad chip was in the address decode logic that enabled the 6530's ROM. I built the system in the mid-1970's. The CPU and TIM chips were purchased from the Wescon show where they debuted; the Jolt board was purchased a year later after I got tired of trying to wire-wrap what would basically be the same thing. Already getting lazy, so young in life. It's got a Bay Area TVT for the terminal, high speed paper tape reader, and an 8-bit DAC that did data acquisition for my masters project. Blows my mind that an Arduino can do the same, so much better, for so little cost. I have paper tapes for Tom Pitman's Tiny Basic, an assembler and text editor, and a few random utilities from the day. Now all I do is play Hunt the Wumpus on it. Fun times. I wouldn't mind finding any other games, if they even existed.

I remember seeing the KIM-1 in Popular Electronics and wisely deciding to buy a complete computer instead.

Wooo! Congrats on getting the KIM working! That is fantastic, I an excited to see a KIM up and running. I simply know no other way to add the numbers 2 and 3. Believe me, I know how you feel. I have had a KIM for years and have been avoiding plugging it in specifically because of those RIOT chips. As long as I don't try to power it on, it might still be a good and working KIM. I know I can't be the only one with a Schrodinger's KIM in their collection.

Excellent content! One of the best in the retro space.

I think I learned assembly on a kim ! in college in Newfoundland in 1987. I'm not sure but the keypad and display looks familiar. I remember it was in a black suitcase.

Nice! Very satisfying to see life in this old board again.

I have watched Adrians Digital Basement quite a few times. And in some of the videos he has posted where he was repairing Commodore 64's, he has found new chips that are replacements for some of the older Commodore chips. Now I can't say for certain, but maybe someone in the Kim-1 community might know of replacements for the RRIOT chips

awesome to watch whilest making food ^.^ always happy when you upload

Great video, I love seeing old hardware that I know nothing about!

yeah thats a great feeling when you see something runs for the first time. id recommend getting some flux and copper braid for repairing the shorted lines. i also couldnt see buying the hakko at that price and went with a zd-915. That with a hot air gun (for the ground vias) was magic doing some recap work on some motherboards recently.